Delaware court finds AI training on unlicensed copyrighted works infringes, non-generative competitor tool held liable for 2000+ headnote copies

A federal district court in Delaware ruled on February 11, 2025 that Ross Intelligence infringed Thomson Reuters' copyrights by using over 2000 Westlaw headnotes (legal research summaries) to train its non-generative AI legal search tool, rejecting a fair use defense. The court emphasized that Ross' tool directly competed with Westlaw rather than transforming the underlying works, and that intermediate copying was not excused absent necessity for interoperability. The decision signals that unlicensed training data use may face copyright liability, though the court noted generative AI tools and broader applicability remain unresolved, with dozens of pending cases primarily in California and New York federal courts where outcomes remain uncertain.